The primary objective of this research is to adapt and evaluate existing descriptive and classificatory techniques as they apply to prehensile skills in a common laboratory primate, the squirrel monkey. Captive subjects will be filmed while performing in structured prehension tasks. Film records will be analyzed by two methods: cluster analysis (quantitative) and movement notation (qualitative). Determination of the usefulness of these techniques for the study of prehension will be a primary focus of the project. The research addresses theoretical questions raised by the presence of well-developed prehensile skills in non-human primates, such as the degree and functional consequences of variability in prehension between sexes or over tasks. Data bearing on issues of variability and control of fine motor patterns will be generated. The research forms the preliminary portion of a planned long-range research program on the ontogeny of motor and cognitive skills in non-human primates by demonstrating the appropriateness of the techniques, and by providing baseline data on an adult population of one species to be used in the research.